Defence lawyers for five men accused of plotting the 9/11 attacks have challenged the fairness of the military tribunal at Guantanamo Bay.
The defendants, who include the alleged mastermind of 9/11, Khalid Sheikh Mohammed, were formally charged with murder and other offences on Saturday.
None of the defendants has yet entered a formal plea, and during the hearing they mostly remained silent.
The men's lawyers say the court is censoring evidence of torture.
At a joint news conference they complained of what they called "assembly line justice" protected by a "veil of secrecy".
The tribunal will reconvene next month, but several defence lawyers expressed doubts as whether the case would ever come to full trial.